1. Field of the Invention
The present invention relates to intrabuccally dissolving and partially dissolving compressed tablets and a method for their manufacture. The tablets deliver an active ingredient in an easy chew form that quickly disintegrates in the buccal cavity. Particularly, the present invention relates to intrabuccally dissolving and disintegrating tablets comprised of low density granules prepared from inactive and/or active raw material ingredients. The tablets are useful in the pharmaceutical and confectionery fields. The low density granules are prepared from active and/or inactive raw material ingredients and low density ingredients such as alkali earth metal salts, water soluble carbohydrates and mixtures thereof. The present invention also comprises a process for the preparation of the low density granules, and a process for the preparation of tablets using the low density granules.
2. Description of Related Art
Compressed tablets are solid dosage forms prepared by compacting a formulation containing an active ingredient and excipients selected to aid the processing and improve the properties of the product. The term "compressed tablet" generally refers to a plain, uncoated tablet for oral ingestion, prepared by a single compression or by pre-compaction tapping followed by a final compression. Such pre-compaction tapping does not necessarily overcome the flow and die fill problems associated with the use of very fine particles prior to the final compression of the tablets.
Tablets can be made in many sizes and shapes, with a variety of properties. Tablets are the most widely used of all pharmaceutical dosage forms for a number of reasons. They are convenient, easy to use, and less expensive to manufacture than other oral dosage forms. They deliver the intended dose with a high degree of accuracy. A popular type of tablet that has been developed for special application is the buccal tablet.
Despite their benefits, buccal tablets have certain drawbacks. Foremost is the fact that buccal tablets dissolve slowly in the buccal pouch. In general, the hardness levels of compressed tablets are not adequate for fast disintegration in the buccal cavity and ultimately in the digestive tract through oral administration. This is especially disconcerting to those consumers unable to swallow or chew conventional compressed tablets.
Consequently, there is a great need for a tablet that rapidly dissolves and absorbs with sufficient speed so that the tablet can be used by consumers who otherwise do not use tablets. Others have recognized and worked on the problem. U.S. Pat. No. 4,855,326, describes a melt spinnable carrier agent such as sugar combined with a medicament that is converted into fiber form by melt spinning with "cotton candy" fabricating equipment. The as-spun product is converted to compacted individual dosage units that reportedly display rapid entry into solution upon contact with a solvent.
While the melt spinnable product confers advantageous properties amenable to consumers who are unable to swallow or chew conventional compressed tablets, they are not without certain disadvantages. Most critical is that the melt spinning step is required in addition to direct compression techniques. A procedure employing only direct compression is by far the desired method from the standpoint of processing procedures, equipment and materials.
U.S. Pat. No. 4,684,534 discloses tablets having a harder outer shell that inhibits penetration of liquid into the interior of the tablet. The interior of the tablet is softer and quickly liquifies when the shell is broken and the interior contacts liquid.
U.S. Pat. No. 5,178,878 discloses a tablet made from microparticles and an effervescent disintegration agent. When the tablet is taken orally, the effervescent disintegration agent aids in rapid dissolution of the tablet.
U.S. Pat. No. 5,501,861 discloses fast dissolving tablets. The tablets have a porosity of 30 to 70%, a hardness of 3 to 20 kg and a falling impact strength of 0 to 70%. The tablets are made with water-soluble carbohydrates and 1 to 3% by weight of water. The tablets are made by adhering particles of carbohydrate to each other by moistening the surfaces of the particles with the water, compressing the particles and removing the water.
U.S. Pat. No. 5,576,014 discloses an intrabuccally dissolving compressed molding made from a granulated saccharide having low moldability and a saccharide having high moldability. The blending ratio of the high moldability saccharide to the low moldability saccharide is 2 to 20% by weight. The moldings quickly disintegrate in the buccal cavity and have adequate hardness.
German Patent Document 1,617,638 teaches sorbitol for use as a tablet binder. The density of the sorbitol used is between 0.53 and 0.545 gms/cm.sup.3.